Device for detaching parietal thrombi from a blood vessel

ABSTRACT

A device for detaching parietal thrombi from a bodily vessel is described, said device having a catheter, along the catheter longitudinal extent of which at least one catheter section is provided in which the associated catheter wall has at least one wall opening which passes completely through the catheter wall. 
     The invention is characterised in that the catheter wall along the least one catheter section is made of a resiliently deformable material, in that the at least one wall opening is designed as a separating gap winding helically around the catheter wall at least in parts along the catheter section, in that the catheter has, in the distal direction from the wall opening, a fixing means which permits releasable fixing of the catheter on a bodily vessel, in that the catheter can be converted, exclusively by an external mechanical constraint in the form of a torque acting torsionally on the catheter, from a state with a relatively small catheter outer diameter to a state with a relatively large catheter outer diameter, by way of a resilient change in shape, wherein the helically winding separating gap widens from a closed gap state to an opened gap state, and in that the catheter, in the absence of the external constraint, spontaneously adopts the state with the relatively small catheter outer diameter, due to the resilient restoring forces inherent to the material, and the separating gap adopts the closed gap state.

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to PCT Application No. PCT/EP2013/003166, filed on Oct. 21, 2013, and German Application No. 10 2012 021 729.3, filed Nov. 11, 2013, which applications are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a device for detaching parietal thrombi from a bodily vesselthe device having a catheter which along a catheter longitudinal dimension at least one catheter section is disclosed in which an associated catheter outer wall diameter is variable and in which the catheter wall has at least one wall opening which passes completely through the catheter wall.

2. Description of the Prior Art

A large number of catheter-based, medical instruments that are used for gentle ablation of deposits on vessel inner walls caused by ageing or disease are known for the interventional treatment of vessels which have been narrowed by parietal thrombi and through which bodily fluids flow. The medical instruments, which are often also referred to as thrombectomy catheter systems, each have a catheter tip suitable for tissue ablation.The catheter tip is used to dispose of the ablated thrombus material outside the body, usually in a manner assisted by a vacuum within the catheter lumen.

To this end, a mechanical thrombectomy catheter system having a multi-lumen catheter, which can be positioned with the aid of a guide and positioning wire relative to a thrombosis, which is initially pre-treated with a lysis solution via a rinsing channel which is disclosed in US Published Application No. 2010/0087844 A1. A scraping tool, formed as a basket then exits the catheter at the distal end via an instrument channel running along the catheter and fragments the surrounding thrombus material by way of an axial movement in the catheter. The separate thrombus material fragments can be collected and brought outside the body via a further aspiration channel provided along the catheter.

In contrast to the axially movable, basket-like scraping tool, as explained above, US Published Application Nos. 2006/0074441 A1 and 2011/0040314 A1 disclose thrombus material removal tools formed a wire, which each have, at a tool tip, a sinusoidal wire which rotates about the wire longitudinal axis, which has the effect of a spindle-shaped cutting structure. Upon contact with thrombus material adhering to the vessel wall, the tool comminutes the thrombus material from rotary shear forces and can remove the comminuted material. Detached thrombus material fragments in this case are conveyed outside the body using a suitably placed aspiration catheter.

A further thrombus material ablation tool is described in US Published Application No. 2006/0064073 A1, which describes a tool catheter which is guided through an aspiration catheter. On the distal catheter region an ablation tool that can be spread apart in a wedge-like manner radially relative to the catheter axis is mounted. The ablation tool can separate and fragment intravascular thrombus material on account of a rotary movement about the catheter axis. Due to the tool, limbs oriented in a wedge-like manner and due to the suction effect prevailing by means of the aspiration catheter, the fragmented thrombosis material particles pass in a proximal direction from the tool catheter tip into the aspiration catheter.

An advantageous addition to the mechanical thrombectomy catheter system described above is described in US Published Application No. 2006/0253145 A1, in which an inflatable balloon is provided at the distal end of the tool catheter. The balloon on the one hand centers the tool catheter axially within the vessel and thus relative to the thrombus material to be removed. On the other hand, the tool catheter ensures that no fragments of thrombus material, which are separated from the vessel wall, can pass distally from the fan-shaped, expanded and rotating removal tool into the bloodstream in an uncontrolled manner.

US Published Application No. 2007/0208361 A1 describes an atherectomy catheter system that has an aspiration catheter beyond which a radially expandable stent graft and also a centrally guided needle protrude distally, which are mounted jointly in a co-rotating manner, and which punctures, separates and comminutes thrombus material, in a manner comparable to a drill head, by being advanced in the distal direction along a stenosed bodily vessel. The fragmented thrombus material pieces are brought outside the body via the aspiration catheter.

A further method for the local separation of stenosed tissue regions is provided by catheter systems having cutting tools. A catheter at the distal peripheral outer region having individual inflatable bodies arranged in the peripheral direction so as to individually position the axial placement of the distal catheter tip relative to a vessel to be treated, is disclosed in US Published Application No. 2009/0270800. Furthermore, a cutting blade, that can be guided via the catheter tip, is provided within the catheter. The cutting blade separates thrombus material from the vessel wall and the separated thrombus material pieces then pass via an aspiration channel along the catheter arrangement.

A comparable catheter arrangement is disclosed in WO 2010/132748 A1, which also provides a cutting tool that is mounted in a guidable manner both axially by a radially splayable catheter tip and via an opening provided laterally along the catheter arrangement.

A thrombectomy catheter through which fluid flows is disclosed in US Published Application No. 2008/0300532 which is positioned by a guide wire extending along a stenosed vessel site. The catheter has, along a distal catheter section, at least two openings oriented transversely to the catheter longitudinal extent, with one opening serving as fluid discharge opening from which a fluid flow exits transversely to the vessel longitudinal extension onto the thrombus material to be removed and detaches this material locally from the vessel inner wall to form very small thrombus material fragments. The detached thrombus fragments pass via the second opening into the interior of the catheter, along the length of which fluid flow containing the thrombus material is conveyed outside the body.

Lastly, DE 10 2009 017 050 A1 describes a device for detaching material from a bodily vessel using a catheter, A tool catheter can be positioned relative to a thrombosis to be removed. The tool catheter has a stent-shaped catcher element, which spontaneously expands radially when removal distally from the catheter. The catcher element has entry openings formed as slots, through which the material to be removed, in particular thrombi, infiltrates the interior of the catcher element. As a result of axial and also rotary movements of the tool catheter, the thrombus material protruding through the entry openings into the interior of the catcher element is detached on account of shear forces and is conveyed outside the body as fragmented individual pieces by application of a vacuum applied within the tool catheter. In order to remove the catheter arrangement from the vessel, the catcher element is drawn in the proximal direction by radially acting compressive forces into the channel and is removed from the body in this compressed state.

All of the above, known solutions constitute catheter designs that are technically complex in that operative handling places high demands on the operator, especially since the tools for local intravasal removal of parietal thrombi have sharp edges, requiring operation with great care in order to avoid causing damage to vessel walls.

The devices disclosed U.S. Pat. No. 7,063,671 for removing samples or for removing polyps from a body of a patient have actuators made of electroactive polymer material, which can be contracted and expanded by electrical stimulation. Openings in the device can be widened by appropriate actuation of the actuators so as to grasp a sample or the polyp.

US Published Application No. 2010/0125239 explains, as an alternative to cutting, ablating or vaporising stenosis treatment methods, a catheter having an inflatable balloon, with which medicines can be applied at a specific site within a lumen, for example an artery. The catheter thus has a balloon which is surrounded by a porous membrane. A medicine is located in the space between balloon and membrane. By activating electrodes located on the membrane and as a result of the thermal energy supplied during this process, the membrane pores open and molecules of a medicine are pushed by the pressure produced by the balloon through the membrane pores to the tissue to be treated. The balloon also causes a radial expansion, under which the catheter comes into contact with the surrounding tissue.

A catheter device for detaching parietal thrombi that is more economical compared with the above, known catheter solutions and that is more easily operated by the operator can be found in German patent application DE 10 2011 120 004.9. The device utilizes the resilient properties of a tubular catheter which is formed from an elastomer, in the catheter wall of which wall openings which pass completely through the catheter wall are formed. The wall openings, with the aid of a displacement body, which is insertable along the catheter, can be converted by radial extension of the tubular catheter into an expanded opening state. Parietal thrombus material infiltrates the region of the expanded catheter wall openings with suitable intravascular positioning of the catheter. Following removal of the displacement body from the catheter and an accompanying resilient return of the expanded catheter into the original state thereof, the thrombus material is fixedly clamped within the catheter wall openings when the openings are made smaller, thus producing shear forces, and the thrombus material is then removed by extracorporeal removal of the catheter.

US Published Application No. 2005/0080430 discloses a catheter having an expandable, distal end, including a medical device located in front of the catheter end in a body lumen. The medical device has a larger diameter than the catheter and can be removed or brought to another location within the body. The end of the catheter has slots, which at least partially do not run parallel to the longitudinal extension of the catheter. The slotted region is held together by a ductile elastomer layer arranged on the outer side.

The invention is a device for detaching parietal thrombi from a bodily vessel, which device is as simple as possible, economical and easily operable for the operator, such that vessel wall damage can be largely eliminated. In addition, parietal thrombus material is removed from the vessel wall reliably and efficiently, with as little residue as possible, and the separated thrombus fragments are conveyed reliably outside the body.

Proceeding from the German Patent Application No. DE 10 2011 120 004.9, the device according to the invention similarly utilizes the resilient properties and the associated resilience restoring forces of a catheter section a resiliently deformable material for the purposes of receiving and also separating parietal thrombus material from a bodily vessel, while eliminating the need for a displacement body of the prior art explained above. The new catheter device of the invention has a simpler design and can be handled more easily and also can be produced more economically than the prior art.

The device of the invention for detaching parietal thrombi from a bodily vessel has a catheter, extending along the catheter longitudinal axis including at least one catheter section in which an associated catheter wall has at least one wall opening which passes completely through the catheter wall transversely to the catheter longitudinal extent. The catheter or at least one catheter section is made of a resiliently deformable material. The at least one wall opening includes a separating gap winding helically around the catheter wall at least in parts along the catheter section. The separating gap which preferably winds helically over the entire axial extent of the catheter section is preferably formed as a cut passing completely through the catheter wall, that is no catheter wall material is removed in order to form the cut, such that the catheter wall section faces running along the helically winding separating gap and faces one another and contacts each other in a planar manner.

The catheter has, in the distal direction from the at least one wall opening which is a helical winding separating gap, a fixing device which permits temporary, that is a releasable fixing of the catheter on or within a bodily vessel. The fixing device is formed in particular in such a way that the catheter can be anchored or can be fixed intracorporeally to be secured against rotation about its catheter longitudinal axis where possible.

In a preferred embodiment the fixing device is formed as a dilatable balloon, which is fixedly mounted preferably on the distal catheter tip or at least in the distal direction from the at least one helically winding separating gap along the catheter and can be dilated via a lumen guided within the catheter by filling with a suitable gaseous or liquid medium. Alternatively to a fixed mounting of a balloon on the catheter, it is also possible to provide a balloon catheter that can be handled separately from the catheter and which slides through the inner lumen of the catheter in the distal direction until the balloon is positioned at the distal end of the catheter or protrudes therebeyond in the distal direction. As a result of appropriate inflation, the balloon can securely fix the catheter within a vessel distally, such that the catheter is fixed at one end in particular in a manner secured against rotation relative to its catheter longitudinal axis.

Of course, it is possible and conceivable to form the fixing device in another way, for example in the form of anchoring structures, which are dynamically extendable or unfoldable from the catheter at the distal region of the catheter. Anchoring structures of this type have long been known to the person skilled in the art and therefore do not require a detailed description.

The catheter according to the invention as explained above is positioned, for the purposes of gentle intravascular ablation of parietal thrombus material, within a bodily vessel in such a way that the catheter section having the at least one helically winding separating gap is positioned directly along an intravasal, parietal thrombus deposit. In this position, the catheter must be fixed preferably at the distal end by the fixing device in such a way that the catheter is fixed axially along the vessel, but in particular in a manner secured against rotation. In this state, an external mechanical constraint must be exerted via an extracorporeally accessible catheter section onto the catheter as a torque acting torsionally along the catheter, so that a direction of rotation forming the basis of the torque is oriented against the winding direction associated with the helically winding separating gap. The torque can be produced in metered form by manually twisting the catheter or with the aid of a rotary drive, driven by electric motor, mounted suitably on the proximal end of the catheter.

As a result of the fixing of the catheter at the distal end by the fixing device, which takes up the torque at the end, the torque acting along the catheter can convert the catheter section, along which the at least one helically winding separating gap extends, from a state with a relatively small catheter outer diameter into a state with a relatively larger catheter outer diameter by way of a resilient change in shape of the catheter wall so that the helically winding separating gap widens from a closed gap state to an opened gap state. Due to the radial widening of the catheter section, the catheter outer wall is pressed against parietal thrombi, which project at least in part into the space of the opened separating gap.

Once the external mechanical constraint has been stopped, that is, once the torque acting torsionally on the catheter has been eliminated, the catheter can spontaneously resume a state with the relatively smaller catheter outer diameter on account of resilient restoring forces inherent to the material, causing the forcibly opened separating gap convert back to the initial, closed gap state. Due to the width reduction, thrombus material projecting within the separating gap are positively clamped and ultimately sheared off from other parietal residual material.

The thrombus material advantageously can be sheared off in an assisted manner so that a torque oriented in the winding direction of the helically winding separating gap is introduced along the catheter from the proximal end. As a result, the gap sectional faces delimiting the helically winding separating gap on either side can be pressed against one another with an additional force and therefore the shear-off forces directed onto the thrombus material can be increased.

For the purposes of the most complete possible grasping, ablation and lastly extracorporeal removal of parietal thrombus material from a bodily vessel, it is advantageous to apply a vacuum along the catheter, that is, along the lumen enclosed by the catheter. That is the vacuum is applied in particular along the catheter section provided with the at least one helically winding separating gap to aspirate the parietal thrombus material through the separating gap in the opened state into the interior of the catheter section, and to also reliably store the material there in a re-closed state of the catheter. For this purpose, in one alternative embodiment, the catheter has at the proximal catheter end thereof a connection structure for the fluid-tight connection to a suitable vacuum source or aspiration source.

It is of course possible to provide two, three or more helically winding separating gaps within the catheter wall along the catheter section, which is preferably made of a resiliently deformable elastomer as in a cylindrical or tubular form comprising an inner catheter lumen. Each of the separating gaps has an identically oriented winding direction. The helicity of the at least one separating gap is preferably designed with a uniformly constant pitch, which preferably extends over the entire length of the catheter section. Nevertheless it is possible to provide at least two axial regions along the catheter section, within each of which axial regions the helically winding separating gap has a different pitch. If it is necessary by way of example to detach the greatest possible quantities of parietal thrombus material from a vessel wall region, a catheter designed in accordance with the invention is suitable, having at least one helically winding separating gap with the pitch selected to be minimal, that is, as many turns as possible are provided within an axial region along the catheter section.

A further advantageous embodiment has, along the catheter section and in addition to the least one helically winding separating gap, at least one wall opening which passes completely through the catheter wall, which in contrast to the design of the least one helically winding separating gap is formed by a material cutout from the catheter wall and preferably has a maximum opening width from 0.1 to 20 mm. The at least one further wall opening retains its opening geometry, which is preferably round, oval, n-cornered, or has an opening shape deviating herefrom, largely in an unaltered manner, even in the case of an above-explained change in shape of the catheter caused by a torque acting thereon.

The at least one further wall opening serves as an aspiration opening in the case of a vacuum applied within the lumen enclosed by the catheter, as a result of which vacuum parietal thrombus material can be sucked in, primarily in the above-described closed catheter state, which the catheter adopts during an intracorporeal insertion and positioning and also for a subsequent extracorporeal removal.

Both the process of ablation of parietal thrombus material with the at least one helically winding separating gap and also the wall openings additionally within the catheter wall along the catheter section can be assisted in a preferred further embodiment of the catheter according to the invention by axial and/or radial movements of the catheter relative to the stenosed vessel site. The relative movements can be be performed either manually by the operator or can be assisted by a vibrator unit suitably provided proximally on the catheter.

In principle, the catheter system according to the invention does not have any cutting tools that could potentially damage the healthy vessel wall and that are to be guided intravasally separately from the catheter, as is the case in the relevant prior art. Rather, the catheter system according to the invention enables a gentle and completely damage-free thrombus material ablation from the vessel inner wall, especially because, when the healthy vessel inner wall is reached by the catheter, the healthy vessel wall material bears against the catheter outer wall parallel thereto and cannot reach into the widened separating gap. The catheter provided with at least one lateral separating gap opening and where appropriate with additional wall openings thus makes it possible to remove merely tissue material adhering to the vessel wall with jutts out beyond the vessel wall surface.

In order to completely eliminate parietal thrombus material, it is usually necessary to position the catheter relative to the thrombus material present intravasally and to perform the above-described separation process a number of times in succession. It is indeed possible to withdraw the catheter in the proximal direction after each individual tissue separation by a working catheter also introduced intracorporeally and to clean the catheter accordingly of the separated tissue material extracorporeally in order to reposition the catheter intracorporeally. However, it is also advantageous in cases in which larger quantities of thrombus material are to be removed at a stenosis to attach a vacuum source to the catheter at the proximal end, via which vacuum source the separated thrombus material can be brought outside the body within the catheter in the proximal direction.

The catheter wall of the catheter, in particular in the region of the catheter section, is made of a biocompatible elastomer, which is made of at least one material from the following materials:

poly(methyl methacrylate) (PMMA), polytetrafluoroethylene (PTFE), polyurethanes, polyether urethanes, silicone polyether urethanes, silicone polyurethanes, silicone polycarbonate urethanes, polyolefin elastomers, polyisobutylenes, fluorosilicones, polyvinyl chloride (PVC), polydimethylsiloxane (PDMS), polylactides, polyethylene, polybutylmethacrylate, polyacrylamide, polyacrylonitriles, polyamides, polyetheramides, polyethylene amine, polyimides, polycarbonates, polycarbonate urethanes, polyvinyl ketones, polyvinyl halides, polyvinylidene halides, polyvinyl ether, polyisobutylenes, polyvinyl aromates, polyvinyl ester, polyvinyl pyrrolidones, polyoxymethylenes, polytetramethylene oxide, nylon or polyester.

The above materials enable a simple and economical production of the catheter according to the invention in that at least one helically winding separating gap in the form of a mere cut along the catheter section is formed with the use of conventional cutting methods. Due to the cutting process, the catheter does not experience any material removal or virtually no material removal, such that two separating gap sectional faces bearing directly against one another along the catheter section are formed and are delimited respectively by a sharp cut edge arranged radially inwardly and outwardly of the catheter. Above all, the radially outer cut edge assists a complete separation from the vessel inner wall of thrombus material to be ablated.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by way of example hereinafter without limitation of the general inventive concept on the basis of exemplary embodiments with reference to the drawings, in which:

FIGS. 1 a and b show schematic illustrations of a catheter formed in accordance with the invention a) in a state free from external forces and b) with action of a torque acting along the catheter ;

FIGS. 2 a to e show variants for a fixing mechanism ;

FIG. 3 shows a catheter section placed within a hollow vessel opposite a thrombus ; and

FIGS. 4 a and b show schematic illustrations of a further embodiment of a catheter formed in accordance with the invention a) in a state free from external forces and b) with action of a torque acting along the catheter.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 a shows, in a highly schematic manner, a catheter 1 formed in accordance with the invention, which is cylindrical or tubular having a catheter wall made of a biocompatible resilient elastomer. At least one catheter section 2 is provided along the catheter 1, in which catheter section is formed a helically winding separating gap 3, which is produced with a non-material-removing separation procedure, preferably by way of a cutting procedure, in the form of an incision or cut which passes completely through the catheter wall. The catheter section 2 does not experience any externally visually perceptible surface disruption on account of the helically winding separating gap 3. Rather, the separating gap 3 which is designed as a helical incision has a closed form, that is, a form without a gap opening. In the case illustrated in FIG. 1 a, the helical separating gap 3 has two and a half turns 31, each with constant pitch.

If the catheter illustrated in FIG. 1 a provided with at least one helically winding separating gap 3 is fixed at the distal catheter tip 4 thereof and if in addition a torque D is applied at the proximal end to the catheter 1 and the direction of rotation of the torque is oriented opposite the winding direction of the helically winding separating gap 3 formed in the catheter 1, the separating gap 3 opens, wherein the opposite sectional faces 32 and 33 of the separating gap 3 are separated from one another, as is illustrated in FIG. 1 b. At the same time, the catheter outer diameter d₂ widens significantly, with d₂>d₁, as can be seen in the illustration according to FIG. 1 b compared with FIG. 1 a. The torsion-induced gap opening of the separating gap 3 is also accompanied by a longitudinal extension of the catheter 1 in the region of the catheter section 2.

If, by contrast, the torque D reduces to zero, the widened catheter section 2 illustrated in FIG. 1 b returns spontaneously into the initial starting form illustrated in FIG. 1 a on account of resilient restoring forces inherent in the material of the catheter. The opened separating gap 3 thus closes, as is illustrated in FIG. 1 a.

The above-described mechanism of opening and closing of the separating gap 3 winding helically around the catheter section 2 in the longitudinal direction is suitable for the separation of parietal thrombi within bodily vessels through which blood flows. For the ablation process, it must be ensured that the catheter 1 positioned intravascularly opposite a thrombus is fixed at its distal end 4 or at least distally of the catheter section 2 relative to the bodily vessel with the aid of a suitable fixing device. In particular, it must be ensured with regard to the fixing that the catheter 1 is fixed within the hollow vessel in a manner secured against rotation about its longitudinal axis so as to take up the torque necessary in order to open the separating gap and so as to be supported with respect to the hollow vessel. To this end, a dilatable balloon 5 (see FIG. 2 a), which is mounted on the distal end 4 of the catheter 1 and which can be filled with a suitable inflation medium, such as air or a liquid medium, via a supply channel (not illustrated) running accordingly within the lumen of the catheter 1, is preferably used as suitable fixing device. The balloon 5 can be mounted either fixedly on the distal end of the catheter 1 or can be provided separately from the catheter 1 and advanced distally by being slid through the inner lumen of the catheter 1. Radiopaque markings 7, and 7′ are formed in or mounted on the catheter 1 distally and proximally adjacently to the catheter section 2, along which the helically winding separating gap 3 is mounted.

FIG. 2 b shows a partial longitudinal section of a catheter 1 placed within a hollow vessel 10. The catheter has a helically winding separating gap 3 along a catheter section 2. The separating gap 3 ends just before the distal end 4 of the catheter 1. At least in this region close to the distal end 4, the catheter 1 is connected to a balloon catheter 6 guided in parallel outside the catheter 1. The connection 18 between the catheter 1 and balloon catheter 6 is designed so that the balloon catheter 6 is fixedly connected at least in the peripheral direction of the catheter 1, such as, for example, of an adhesively or integrally bonded connection.

The balloon catheter 6 surrounds an inner lumen, which can be connected at the proximal end to an inflation arrangement (not illustrated), of which the balloon 5 mounted on the balloon catheter 6 at the distal end can be inflated. The balloon 5 is preferably combined with a net-like, radially expandable stent 15, which the balloon 5 in the inflated state can press from the inner wall against the bodily vessel inner wall 9 under the application of force to thus ensure on the one hand that the catheter 1 is held within the bodily vessel 10 in a manner secured against rotation, and on the other hand to allow the stent 15 to widen the vessel locally in situ following corresponding deflation of the balloon 5 and removal in the proximal direction.

While the inflated stent balloon 5/15 is pressed against the vessel inner wall 9 and thus locally closes the vessel, which the balloon inflation typically lasting 1 to 5 minutes, the helically cut catheter section of the catheter 1 is deformed torsionally by application of a torque along the catheter 1 from the proximal catheter end, wherein the separating gap 3 opens. The parietal thrombus is aspirated, by an aspiration vacuum applied at the proximal end along the catheter lumen, on the catheter side of the balloon 3 and more specifically via the rotated and therefore opened separating gap 3 of the helically cut catheter section. For the purpose of the intracorporeal navigation of the catheter 1, a guide wire 16 guided in an additional lumen running within the catheter lumen also runs in the manner of an “over the wire” configuration, which projects distally from the catheter 1 and runs laterally past the dilated balloon 5 or runs therethrough through a corresponding cutout.

It must be noted that the intravasal catheter section, along which the helically winding separating gap 3 is formed, typically has a length of 2-50 cm and is positioned completely intravascularly, such that no other tissue material or even air can be aspirated through the helically winding separating gap 3.

In a further embodiment, which is shown in FIG. 2 c, a balloon catheter 6 is guided outside along the catheter 1 in a longitudinally movable manner. In order to connect the balloon catheter 6 in a manner secured against rotation relative to the catheter 1, this has, at its distal end region, an outer, short additional lumen 19, through which the balloon catheter 6 is guided.

With the aid of a guide wire 16, the entire catheter 1 together with the balloon catheter 6 mounted thereon in a longitudinally movable manner is guided intravasally and is positioned relative to a parietal thrombus, wherein the balloon 5 additionally can be advanced in the distal direction relative to the catheter 1 to place the balloon 5 at a distance from the distal end 4 of the catheter 1 and to inflate the balloon in this position. Similarly to the exemplary embodiment according to FIG. 2 b, the balloon 5 is embodied as a stent balloon 5/15.

The guide wire 16 runs in this case in the form of a monorail configuration, that is, largely outside the catheter 1. At the distal region of the catheter 1, the guide wire 16 enters a lumen guided along the catheter 1, which in the illustrated case runs as an additional lumen 14 within the balloon catheter 6. In this regard see the detailed illustration for FIG. 2 c.

FIG. 2 d shows a further embodiment that, instead of the above balloon catheter or stent balloon, has as fixing device a catheter 20 with a self-expanding filter sail arrangement 17, which is guided similar to a longitudinally movable manner at the distal end 4 of the catheter 1 through an additional lumen 19 mounted fixedly thereon. The filter sail arrangement 17 has two self-expanding filter sails 17′ and 17″ arranged along a wire 20, which are preferably designed in a basket-like manner and are made of a shape-memory material, for example an Ni-Ti alloy. For the intracorporeal insertion of the entire catheter arrangement, that is, the catheter 1 with catheter 21 mounted thereon, both filter sails 17′ and 17″ are located within the catheter 21 in a folded state. Following appropriate intravascular positioning the catheter 1 via a guide wire (see FIG. 2 c), the filter sail arrangement 17 can be unfolded sequentially by withdrawing the hollow catheter relative to the wire 20 with the filter sail arrangement 17 mounted thereon on account of the shape-memory effect inherent to the filter sail material. That is, the distal-end, smaller filter sail 17″ unfolds first and nestles via its umbrella-like peripheral edge against the inner wall 9 of the bodily vessel. As a result of further withdrawal, the slightly larger filter sail 17′ also unfolds at a distance from the smaller filter sail 17″. In the unfolded state of both sails, which each nestle against the vessel inner wall 9, it is ensured that no ablated thrombus material can travel around in the bodily vessel in an uncontrolled manner, since all tissue material separated from the vessel inner wall 9 is either aspirated through the opened separating gap 3 of the catheter 1 or is caught by the filter sail arrangement 17. On the other hand both braced filter sails 17″ and 17′ ensure the holding torque or counter-torque providing support with respect to the vessel inner wall 9 and necessary for the influence of the torque along the catheter 1 in order to open the helically winding separating gap 3.

Once the tissue has been removed, the catheter 21 is slid forwards distally relative to the wire 20, whereby the catheter 21 initially slides over the larger filter sail and folds this in the manner of an umbrella; See FIG. 2 e. Here, all tissue particles caught by the filter sail 17′ are detained reliably inside the catheter 21. By sliding the catheter 21 further forwards, the smaller filter sail 17″ is stowed in the same way within the catheter 21.

The catheter 1 in all conceivable embodiments also has, for the purpose of a facilitated intracorporeal navigation of the catheter, at least one radiopaque marking 7, on the basis of which an operator can monitor the exact position of the catheter 1 with the aid of suitable X-ray monitoring methods. Two radiopaque markings 7 and 7′ (See FIG. 4 a) preferably delimit, distally and proximally, the catheter region 2 along which the helically winding separating gap 3 is formed, such that an operator is always aware of the intracorporeal position of the entire catheter section 2 during the intervention.

Following appropriate positioning and anchoring of the catheter 1 within the hollow vessel, the catheter 1 must be opened along its helically winding separating gap 3. To this end, an operator exerts a torque D having a direction of rotation oriented against the winding direction of the helically winding separating gap 3 onto the catheter 1 from the proximal end of the catheter, either manually or with the aid of a suitable rotating device 8 (See FIG. 1 a). Due to the separating gap opening, the catheter outer diameter d₂ also enlarges at the same time and nestles under application of a compressive force against the inner wall 9 of a hollow vessel 10; See FIG. 3 in this regard. Parietal thrombus material 11 can now infiltrate into the opened separating gap 3. This process of the infiltration of thrombus material through the splayed separating gap 3 into the lumen of the catheter 1 can be assisted advantageously by application of an aspiration vacuum along the catheter lumen. To this end the catheter 1 has, in the proximal region, a fluid-tight connection structure for the application of a suitable vacuum source 12 (see FIG. 1 a).

Following corresponding removal of the torque D, the separating gap 3 shown in FIG. 3 in the opened illustration closes and at the same time shears off thrombus material 11, which remains on the inner wall 9 and reaches into the interior of the catheter 1, from the inner wall 9 of the hollow vessel 10. As a result of removal in the proximal direction, the thrombus material can thus be reliably conveyed outside the body in the interior of the catheter.

FIGS. 4 a and b show a further alternative exemplary embodiment for forming the catheter 1 according to the invention, which, in addition to the helically winding separating gap 3 along the catheter section 2, has wall openings 13 which pass completely through the catheter wall 3 and which, in contrast to the separating gap 3, are formed in the catheter wall by way of a material-removing procedure, for example by way of a punching procedure, or a mechanical or thermal material-removing abrasive procedure. The wall openings 13 retain their opening geometry in an unaltered manner irrespective of the resilient change in shape of the catheter 1 and, in conjunction with a vacuum application in the interior of the catheter 1, enable additional possibilities for the safe ablation and reliable storage of separated parietal thrombus material in the interior of the catheter 1.

The dimensioning of the catheter 1 according to the invention is dependent on the geometric conditions of intracorporeal hollow vessels. The axial length of the catheter section 2 along which the least one helically winding separating gap 3 is provided thus measures approximately between 1 cm and 1 m. Of course, it is possible to form one or more helically winding separating gaps along the catheter 1 in different axial regions, which are distanced axially from one another.

Suitable catheter outer diameters that the catheter adopts in a force-free state are typically between 1 mm and 25 mm, wherein the catheter has a catheter wall thickness between 0.1 mm and 2.5 mm. In the case of the torque-induced widening of the catheter, the opened separating gap typically has gap widths between 0.1 mm and 50 mm, preferably between 0.5 mm and 10 mm.

The additional wall openings 13 illustrated in FIGS. 4 a and b typically have opening widths from 0.1 mm to 20 mm.

The catheter 1 according to the invention, for the purpose of the ablation of parietal thrombus material deposits, therefore does not require any cutting tools to be handled in addition to the catheter or any displacement bodies radially widening the catheter, but rather the catheter designed in accordance with the invention is to be fixed intravasally and is to be subjected exclusively to a torque, as a result of which the catheter deploys its full functionality.

LIST OF REFERENCE NUMERALS

-   1 catheter -   2 catheter section -   3 helically winding separating gap -   31 turn -   32 and 33 sectional faces -   4 distal catheter end -   5 balloon -   6 balloon catheter -   7 and 7′ radiopaque marking -   8 rotary motor -   9 vessel inner wall -   10 hollow vessel -   11 thrombus material -   12 vacuum source -   13 wall opening -   14 additional lumen -   15 Stent -   16 guide wire -   17 filter sail arrangement -   17′ and 17″ filter sail -   18 connection -   19 additional lumen -   20 wire -   21 catheter 

1-19. (canceled)
 20. A device for detaching parietal thrombi from a bodily vessel, the device including a catheter, at least one catheter section disposed longitudinally relative to the catheter, a catheter wall including at least one wall opening passing completely through the catheter wall, wherein: the catheter wall disposed longitudinally relative to the least one catheter section comprises a resiliently deformable material; the at least one wall opening includes a separating gap winding helically around the catheter wall at least in parts of the catheter section; the catheter has, in a distal direction from the separating gap, a fixing device for releasably fixing the catheter to the bodily vessel; the catheter is convertable by a torque acting torsionally on the catheter, from a state with a smaller catheter outer diameter to a state with a larger catheter outer diameter, resulting from a resilient change in shape, wherein the helically winding separating gap widens from a closed gap state to an opened gap state; and the catheter, in an absence of an external constraint, spontaneously adopts a state of the smaller catheter outer diameter, due to resilient restoring forces of the deformable material, and the separating gap adopts the closed gap state.
 21. The device according to claim 20, wherein the catheter wall of the at least one catheter section is tubular, comprises an inner catheter lumen, and the resiliently deformable material is an elastomer.
 22. The device according to claim 21, whereas the elastomer is made of at least one material selection from the following materials: poly(methyl methacrylate) (PMMA), polytetrafluoroethylene (PTFE), polyurethanes, polyether urethanes, silicone polyether urethanes, silicone polyurethanes, silicone polycarbonate urethanes, polyolefin elastomers, polyisobutylenes, fluorosilicones, polyvinyl chloride (PVC), polydimethylsiloxane (PDMS), polylactides, polyethylene, polybutylmethacrylate, polyacrylamide, polyacrylonitriles, polyamides, polyetheramides, polyethylene amine, polyimides, polycarbonates, polycarbonate urethanes, polyvinyl ketones, polyvinyl halides, polyvinylidene halides, polyvinyl ether, polyisobutylenes, polyvinyl aromates, polyvinyl ester, polyvinyl pyrrolidones, polyoxymethylenes, polytetramethylene oxide, nylon or polyester.
 23. The device according to claim 20 wherein the at least one catheter section ranging from 1 cm to 100 cm in length, has a resilient section with a catheter outer diameter ranging from 1 mm to 25 mm and a catheter wall ranging in thickness without influence of the external constraint between 0.1 mm and 2.5 mm.
 24. The device according to claim 20, wherein the helically winding separating gap along the at least one catheter section has at least one helical turn.
 25. The device according to claim 20 wherein the at least one helically winding separating gap along the at least one catheter section is formed as an cut which passes completely through the catheter wall, with two sectional faces in contact witih one another directly in the closed gap state.
 26. The device according to claim 20 wherein the at least one helically winding separating gap along the at least one catheter section has a constant pitch.
 27. The device according to claim 20 wherein the at least one helically winding separating gap along the at least one catheter section has at least two axial regions each having a different pitch.
 28. The device according to claim 20 wherein the catheter longitudinal extent includes at least one first catheter section and a second catheter section axially separated from the at least one first catheter section, and the at least one helically winding separating gap is formed in at least two catheter sections each with an identical winding direction.
 29. The device according to claim 20 wherein the fixing device comprises a dilatable balloon, mounted on the catheter and distally separated from the at least one helically winding separating gap or is positionable through the catheter distally therefrom, and the balloon can be inflated via an additional lumen running inside or outside the catheter lumen.
 30. The device according to claim 29, wherein the balloon is surrounded by a radially flexible stent which, in an inflated state of the balloon, bears against a hollow vessel from the inner wall.
 31. The device according to claim 20 wherein the fixing device comprises a mechanically splayable body, mounted on the catheter distally displaced from the at least one helically winding separating gap or positionable through the catheter distally therefrom, and the splayable body is splayed and folded together via an actuation wire guided through an additional lumen running at least inside or outside the catheter lumen.
 32. The device according to claim 31, wherein the splayable body comprises a net and in a splayed state has a filter function for a fluid flowing through the bodily vessel.
 33. The device according to claim 20 wherein the catheter at the proximal end includes a connector to which a vacuum source is attachable.
 34. The device according to claim 20 wherein at least one radiopaque marking is mounted in a region of the catheter tip associated with the catheter and/or along the at least one catheter section.
 35. The device according to claim 20 comprising a further lumen for guiding the catheter via a guide wire attached to an outer side of the catheter from the catheter tip associated with the catheter to the at least one catheter section over a length ranging from 20-50 mm.
 36. The device according to claim 25 wherein sectional faces of the at least one helically winding cut are separated by an external constraint as the catheter is converted from a state with a smaller outer diameter to a state with the larger outer diameter and encloses a helically winding gap having a pitch that is larger than a pitch associated with the helically winding incision in a state with the smaller outer diameter.
 37. The device according to claim 36, wherein in the helically winding gap has a largest gap width b, for which 0.1 mm≦b≦50 mm or 0.5 mm≦b≦10 mm.
 38. The device according to claim 20 wherein at least one further wall opening passes completely through the catheter wall along the at least one catheter section in addition to the at least one helically winding separating gap.
 39. The device according to claim 38, wherein in the at least one further wall opening is formed by a material cutout from a wall of the catheter and has a largest opening width ranging from 0.1 mm to 20 mm. 